All atomic nuclei of the chemical element rubidium are summarized under rubidium isotopes; these all consist of an atomic nucleus with 37 protons and, in the uncharged state, 37 electrons. The difference between each rubidium isotope is based on the number of neutrons in the nucleus.
Natural terrestrial deposits of rubidium consist of the two isotopes rubidium-85 (stable) and rubidium-87 (slightly radioactive) in the ratio 2.6:1 and the atomic mass 85.4678(3) u.
Atomic Mass ma | Quantity | Half-life | Spin | |
Rubidium Isotopic mixture | 85,4678 u | 100 % | ||
Isotope 85Rb | 84,91178974(3) u | 72,17(2) % | stable | 5/2- |
Isotope 87Rb | 86,909180531(6) u | 27,83(2) % | 4.97(3) × 1010 a | 3/2- |
The unstable natural rubidium-87 decays and emits β-rays into the stable nuclide strontium-87. The Rb-87/Sr-87 isotope ratio can be used for radiometric age determination, for example in geology (rocks, magma).
In addition to the naturally occurring isotopes, 30 other unstable rubidium nuclides have been described.
Isotope Nuclide | E | N | Atomic Mass [Nuclear Mass] {Mass Excess} | Spin I (h/2π) | Parent |
---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 |
Rubidium-71 | 7137Rb | 34 | 70.96532(54) u [70.9450233 u] {-32.30421 MeV} | 5/2-~ | |
Rubidium-72 | 7237Rb | 35 | 71.95908(54) u [71.9387833 u] {-38.11673 MeV} | 3+~ | |
Rubidium-73 | 7337Rb | 36 | 72.95053(21) u [72.9302333 u] {-46.08101 MeV} | (3/2-) | 73Sr |
Rubidium-74 | 7437Rb | 37 | 73.944266(3) u [73.9239693 u] {-51.91589 MeV} | 0+ | |
Rubidium-75 | 7537Rb | 38 | 74.9385732(13) u [74.9182765 u] {-57.2187 MeV} | 3/2(-) | |
Rubidium-76 | 7637Rb | 39 | 75.935073(1) u [75.9147763 u] {-60.47911 MeV} | 1(-) | 76Sr |
Rubidium-76m | 76m37Rb | 39 | 75.935073(1) u [75.9147763 u] {-60.47911 MeV} | (4+) | |
Rubidium-77 | 7737Rb | 40 | 76.9304016(14) u [76.9101049 u] {-64.83049 MeV} | 3/2- | 77Sr |
Rubidium-78 | 7837Rb | 41 | 77.928142(3) u [77.9078453 u] {-66.9353 MeV} | 0(+) | |
Rubidium-78m1 | 78m137Rb | 41 | 77.928142(3) u [77.9078453 u] {-66.9353 MeV} | (1-) | |
Rubidium-78m2 | 78m237Rb | 41 | 77.928142(3) u [77.9078453 u] {-66.9353 MeV} | 4(-) | |
Rubidium-79 | 7937Rb | 42 | 78.9239899(23) u [78.9036932 u] {-70.80295 MeV} | 5/2+ | 79Sr |
Rubidium-80 | 8037Rb | 43 | 79.9225164(20) u [79.9022197 u] {-72.17551 MeV} | 1+ | 80Sr |
Rubidium-80m | 80m37Rb | 43 | 79.9225164(20) u [79.9022197 u] {-72.17551 MeV} | (6+) | |
Rubidium-81 | 8137Rb | 44 | 80.918994(5) u [80.8986973 u] {-75.4566 MeV} | 3/2- | 81Sr |
Rubidium-81m | 81m37Rb | 44 | 80.918994(5) u [80.8986973 u] {-75.4566 MeV} | 9/2+ | |
Rubidium-82 | 8237Rb | 45 | 81.918209(3) u [81.8979123 u] {-76.18783 MeV} | 1+ | 82Sr |
Rubidium-82m | 82m37Rb | 45 | 81.918209(3) u [81.8979123 u] {-76.18783 MeV} | 5- | |
Rubidium-83 | 8337Rb | 46 | 82.9151142(25) u [82.8948175 u] {-79.07061 MeV} | 5/2- | 83Sr |
Rubidium-83m | 83m37Rb | 46 | 82.9151142(25) u [82.8948175 u] {-79.07061 MeV} | 9/2+ | |
Rubidium-84 | 8437Rb | 47 | 83.9143752(24) u [83.8940785 u] {-79.75899 MeV} | 2- | |
Rubidium-84m | 84m37Rb | 47 | 83.9143752(24) u [83.8940785 u] {-79.75899 MeV} | 6- | |
Rubidium-85 | 8537Rb | 48 | 84.91178974(3) u [84.8914931 u] {-82.16733 MeV} | 5/2- | 85Kr 85Sr |
Rubidium-85m | 85m37Rb | 48 | 84.91178974(3) u [84.8914931 u] {-82.16733 MeV} | 9/2+ | |
Rubidium-86 | 8637Rb | 49 | 85.91116744(21) u [85.8908708 u] {-82.747 MeV} | 2- | |
Rubidium-86m | 86m37Rb | 49 | 85.91116744(21) u [85.8908708 u] {-82.747 MeV} | 6- | |
Rubidium-87 | 8737Rb | 50 | 86.909180531(6) u [86.8888839 u] {-84.59779 MeV} | 3/2- | 87Kr 87Sr |
Rubidium-88 | 8837Rb | 51 | 87.91131559(17) u [87.8910189 u] {-82.609 MeV} | 2- | 88Kr |
Rubidium-89 | 8937Rb | 52 | 88.912278(6) u [88.8919813 u] {-81.71252 MeV} | 3/2- | 89Kr |
Rubidium-90 | 9037Rb | 53 | 89.914799(7) u [89.8945023 u] {-79.36422 MeV} | 0- | 90Kr |
Rubidium-90m | 90m37Rb | 53 | 89.914799(7) u [89.8945023 u] {-79.36422 MeV} | 3- | |
Rubidium-91 | 9137Rb | 54 | 90.916537(8) u [90.8962403 u] {-77.74528 MeV} | 3/2(-) | 91Kr |
Rubidium-92 | 9237Rb | 55 | 91.919728(7) u [91.8994313 u] {-74.77289 MeV} | 0- | 92Kr 93Kr |
Rubidium-93 | 9337Rb | 56 | 92.922039(8) u [92.9017423 u] {-72.6202 MeV} | 5/2- | 93Kr 94Kr |
Rubidium-94 | 9437Rb | 57 | 93.9263948(22) u [93.9060981 u] {-68.5628 MeV} | 3(-) | 94Kr |
Rubidium-95 | 9537Rb | 58 | 94.929263(22) u [94.9089663 u] {-65.89109 MeV} | 5/2- | 95Kr |
Rubidium-96 | 9637Rb | 59 | 95.934133(4) u [95.9138363 u] {-61.35472 MeV} | 2(-) | |
Rubidium-97 | 9737Rb | 60 | 96.9371771(21) u [96.9168804 u] {-58.51915 MeV} | 3/2+ | |
Rubidium-98 | 9837Rb | 61 | 97.941632(17) u [97.9213353 u] {-54.36944 MeV} | (0,1) | 99Kr |
Rubidium-98m | 98m37Rb | 62 | 97.941632(17) u [97.9213353 u] {-54.36944 MeV} | (3,4) | |
Rubidium-99 | 9937Rb | 62 | 98.945119(4) u [98.9248223 u] {-51.12132 MeV} | (3/2+) | |
Rubidium-100 | 10037Rb | 63 | 99.950352(21) u [99.9300553 u] {-46.24681 MeV} | (3+,4+) | |
Rubidium-101 | 10137Rb | 64 | 100.95400(21) u [100.9337033 u] {-42.84872 MeV} | (3/2+) | |
Rubidium-102 | 10237Rb | 65 | 101.95952(32) u [101.9392233 u] {-37.70688 MeV} | ||
Rubidium-103 | 10337Rb | 66 | 102.96392(43) u [102.9436233 u] {-33.6083 MeV} |
Isotope | Radioactive Decay | Extern | |||
---|---|---|---|---|---|
Half-life | Decay Mode | Probability | Energy | ||
7 | 8 | 9 | 10 | 11 | 12 |
Rb-71 | p → 70 Kr | AL | |||
Rb-72 | < 1.5 μs | p → 71Kr | AL | ||
Rb-73 | 81 ns | EC/β+ → 73Kr p → 72Kr | ? ? | 10.47(20) MeV | AL |
Rb-74 | 64.776(30) ms | EC/β+ → 74Kr | 100 % | 10.416(4) MeV | AL |
Rb-75 | 19.0(12) s | EC/β+ → 75Kr | 100 % | 7.105(8) MeV | AL |
Rb-76 | 36.5(6) s | EC/β+ → 76Kr EC, α → 72Se | > 99 % Spuren | 8.535(4) MeV | AL |
Rb-76m | 3.2(1) μs | ||||
Rb-77 | 3.78(4) min | EC/β+ → 77Kr | 100 % | 5.3390(24) MeV | AL |
Rb-78 | 17.66(3) min | EC/β+ → 78Kr | 100 % | 7.243(3) MeV | AL |
Rb-78m1 | 0.91(4) μs | ||||
Rb-78m2 | 5.74(3) min | EC/β+ → 78Kr Iso → 78Rb | 91(2) % 9(2) % | AL | |
Rb-79 | 22.9(5) min | EC/β+ → 79Kr | 100 % | 3.639(4) MeV | AL |
Rb-80 | 33.4(7) s | EC/β+ → 80Kr | 100 % | 5.7179(20) MeV | AL |
Rb-80m | 1.63(4) μs | ||||
Rb-81 | 4.572(4) h | EC/β+ → 81Kr | 100 % | 2.23826 MeV | AL |
Rb-81m | 30.5(3) min | EC/β+ → 81Kr Iso → 81Rb | 2.4(6) % 97.6(6) % | AL | |
Rb-82 | 1.2575(2) min | EC/β+ → 82Kr | 100 % | 4.404(3) MeV | AL |
Rb-82m | 6.472(6) h | EC/β+ → 82Kr Iso → 82Rb | > 99.67 % < 0.33 % | 4.473(15) MeV | AL |
Rb-83 | 86.2(1) d | EC → 83Kr | 100 % | 0.9200(23) MeV | AL |
Rb-83m | 0.3 ms | ||||
Rb-84 | 32.82(7) d | EC/β+ → 84Kr β- → 84Sr | 96.1(20) % 3.9(20) % | 2.6804(22) MeV 0.8906(23) MeV | AL |
Rb-84m | 20.26(4) min | Iso → 84Rb | 100 % | AL | |
Rb-85 | stable | AL | |||
Rb-85m | 1.015 μs | Iso → 85Rb | 100 % | ||
Rb-86 | 18.642(18) d | EC/β+ → 86Kr β- → 85Sr | 0.0052(5) % 99.9948(5) % | 0.51867(20) MeV 1.7761(2) MeV | AL |
Rb-86m | 1.017(3) min | Iso → 86Rb β- → 85Sr | > 99.7 % < 0.3 % | AL | |
Rb-87 | 4.97(3) × 1010 a | β- → 87Sr | 100 % | 0.282275(6) MeV | AL |
Rb-88 | 17.773(11) min | β- → 88Sr | 100 % | 5.31262(16) MeV | AL |
Rb-89 | 15.32(10) min | β- → 89Sr | 100 % | 4.497(5) MeV | AL |
Rb-90 | 158(5) s | β- → 90Sr | 100 % | 6.585(6) MeV | AL |
Rb-90m | 258(4) s | β- → 90Sr Iso → 90Rb | 97.5(4) % 2.5(4) % | AL | |
Rb-91 | 58.2(3) s | β- → 91Sr | 100 % | 5.907(9) MeV | AL |
Rb-92 | 4.48(3) s | β- → 92Sr β-, n → 91Sr | 99.98 % 0.0107(5) % | 8.095(6) MeV 0.808(8) MeV | AL |
Rb-93 | 5.84(2) s | β- → 93Sr β-, n → 92Sr | 98.61(7) % 1.39(7) % | 7.466(9) MeV 2.1776(9) MeV | AL |
Rb-94 | 2.702(5) s | β- → 94Sr β-, n → 93Sr | 89.5(4) % 10.5(4) % | 10.2829(26) MeV 3.452(8) MeV | AL |
Rb-95 | 377.7(8) ms | β- → 95Sr β-, n → 94Sr | 91.3(3) % 8.7(3) % | 9.228(29) MeV 4.883(20) MeV | AL |
Rb-96 | 203(3) ms | β- → 96Sr β-, n → 95Sr | 86.7(7) % 13.3(7) % | 11.570(9) MeV 5.694(7) MeV | AL |
Rb-97 | 169.1(6) ms | β- → 97Sr β-, n → 96Sr β-, 2n → 95Sr | 74.5(9) % 25.5(9) % ? | 10.062(4) MeV 6.334(9) MeV | AL |
Rb-98 | 114(5) ms | β- → 98Sr β-, n → 97Sr β-, 2n → 96Sr | 86.15 % 13.8(6) % 0.051(7) % | 12.054(16) MeV 6.141(16) MeV | AL |
Rb-98m | 96(3) ms | β- → 98Sr | 100 % | AL | |
Rb-99 | 54(4) ms | β- → 99Sr β-, n → 98Sr β-, 2n → 97Sr | 81.2 % 19.8(20) % ? | 11.400(6) MeV 7.131(5) MeV | AL |
Rb-100 | 51(8) ms | β- → 100Sr β-, n → 99Sr β-, 2n → 98Sr | 93.84 % 6(3) % 0.16(8) % | 13.574(21) MeV 8.203(20) MeV | AL |
Rb-101 | 32(5) ms | β- → 101Sr β-, n → 100Sr | 72(4) % 28(4) % | 12.48(20) MeV 8.90(20) MeV | AL |
Rb-102 | 37(5) ms | β- → 102Sr β-, n → 101Sr | 82(8) % 18(8) % | 14.45(31) MeV 9.55(30) MeV | AL |
Rb-103 | 23 ms | β- → 103Sr β-, n → 102Sr β-, 2n → 101Sr | 13.81(45) MeV 10.48(41) MeV |
Notes (related to the columns):
1 - name of the nuclide, isotope.
2 - E: isotope symbol with mass number (superscript; number of nucleons) and Atomic number (subscript; number of protons).
3 - N: number of neutrons.
4 - relative atomic mass of the Rubidium isotope (isotopic mass including electrons) and the mass of the atomic nucleus in square brackets (nuclear mass, nuclide mass without electrons), each related to 12C = 12.00000 [2]. In addition, the mass excess is given in MeV.
5 - nuclear spin I, unit: h/2π.
6 - source nuclides: Possible, assumed or actual source nuclides (mother nuclides, parent nuclides). If applicable, the corresponding decay modes can be found in the data for the respective starting nuclide.
7 - isotope notation in short form.
8 - decay: half-live of the Rubidium isotope (a = years; ; d = days; h = hours; min = minutes; s = seconds).
9 - decay mode: type of decay into the respective daughter nuclides with n = neutron emission; p = proton emission; α = alpha decay; β- = beta minus decay with electron emission; EC = electron capture; β+ = positron emission; ε = β+ and/or EC; Iso = isomeric transition; CD = cluster decay; SF = spontaneous decay.
10 - decay probability in percent (%).
11 - decay energy; Particle energy related to decay type.
12 - other information and notes: AL = Adopted Levels (link to external data [1]).
Miscellaneous:
()- Numbers in brackets: uncertainty to represent the spread of the reported value.
~ - Theoretical values or systematic trends.
- unlisted-: Nuclides that have already been mentioned in the literature but for some reason can no longer be found in the current nuclide tables because their discovery e.g. has not confirmed.
Nuclide quantity 1) spin | Nuclear magnetic moment μ/μN | Gyromagnetic ratio {Quadrupole moment} | Resonant frequency v0 bei 1 T | Relative sensitivity H0 = const. v0 = const. 3) |
---|---|---|---|---|
85Rb 72,17(2) % 5/2- | +1,35306(4) | 2,5923 {+ 0,276(1)} | 4,1253 | 0,01061 1,1304 |
87Rb 27,83(2) % 3/2- | + 2,75129(8) | 8,7851 {+ 0,1335(5)} | 13,9814 | 0,17704 1,6419 |
1) Quantity Percentage of natural occurrence.
2) Gyromagnetic ratio: 107 rad T-1 s-1
Quadrupole moment: Q [barn] = [100 fm2]
3) Related to 1H = 1,000.
According to the Radiation Protection Ordinance (StrlSchV 2018, Germany), the following values (columns 1 to 7) apply to the handling of Rubidium radionuclides:
Nuclide | Limit Value | HASS limit | SC | Daughter Nuclides | Half-life | |
---|---|---|---|---|---|---|
Rb-79 | 105 Bq | 10 Bq/g | 22.9 min | |||
Rb-81+ | 106 Bq | 10 Bq/g | 0,1 TBq | 4.6 h | ||
Rb-81m+ | 107 Bq | 1000 Bq/g | 30.3 min | |||
Rb-82m | 106 Bq | 10 Bq/g | 6.5 h | |||
Rb-83+ | 106 Bq | 1 Bq/g | 0,1 TBq | 10 Bq -2 | Kr-83m | 86.2 d |
Rb-84 | 106 Bq | 1 Bq/g | 0,07 TBq | 33.5 d | ||
Rb-86 | 105 Bq | 100 Bq/g | 0,7 TBq | 10 Bq cm-2 | 18.6 d | |
Rb-87 | 107 Bq | 10 Bq/g | Unbegrenzt (UL) | 4.8 × 1010 a | ||
Rb-88 | 105 Bq | 10 Bq/g | 17.8 min | |||
Rb-89 | 105 Bq | 10 Bq/g | 15.4 min |
(HASS = High-Activity Sealed Radioactive Sources; SC = surface contamination)
Properties of the Rubidium nucleides
[1] - NuDat: National Nuclear Data Center, Brookhaven National Laboratory, based on ENSDF and the Nuclear Wallet Cards.
[2] - G. Audi et. al.: The NUBASE evaluation of nuclear and decay properties. Nuclear Physics, (2003), DOI 10.1016/j.nuclphysa.2003.11.001.
[3] - Live Chart of Nuclides. Nuclear structure and decay data.
Rubidium: NMR properties - 85Rb-NMR, 87Rb-NMR
[4] - N. J. Stone: Table of nuclear magnetic dipole and electric quadrupole moments. Atomic Data and Nuclear Data Tables, (2005), DOI 10.1016/j.adt.2005.04.001.
[5] - Pekka Pyykkö: Year-2008 nuclear quadrupole moments. Molecular Physics, (2008), DOI 10.1080/00268970802018367.
[6] - Pekka Pyykkö: Year-2017 nuclear quadrupole moments. Molecular Physics, (2018), DOI 10.1080/00268976.2018.1426131.
[7] - N. J. Stone: Table of recommended nuclear magnetic dipole moments. IAEA, (2019).
More sources:
[8] - Isotopic abundances, atomic weights and isotopic masses: see respective keyword.
Last update: 2022-12-12
Perma link: https://www.chemlin.org/chemical-elements/rubidium-isotopes.php
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